Abstract: Evaluation of eco- environmental sensitivity is the precondition of ecological function regionalization, Sis also important means to judge the stability of ecosystem.Which is the important measures to carry out the concept of scientific development and the ecological civilization concept , to speed up the implementation of the planning of main functional area andSbuild national ecological security barrier .The method has great significances to promote sustainable development of longnan city and safeguard national ecological security.According to the basic characteristics of longnan mountain ecosystems,this paper use GIS technology and individually and synthetically evaluate to the ecological sensitivity of land in Longnan city frome the three aspects: soil erosion, rocky desertification and geological disaster. And use trend the surface-method to analyze comprehensive evaluation results.The results showed(1)The regional difference of land ecological sensitivity in Longnan city is obvious, the east is higher than west in the east-west direction,decreasing trend on the whole and present a more obvious "n" word in latitudinal direction, slightly higher than the north in the south；(2)Using natural breakpoint method, Longnan’s eco- environmental sensitivity can be divided into five areas: extremely sensitive area, high sensitive area, medium sensitive area, low sensitive area and insensitive area,accounting for 19.18%, 24.61%, 25.71%,16.88% and 13.61%, respectively;The extremely sensitive area and high sensitive area are mainly distributed in in the surrounding areas of tanchang County and Wudu district, the ecological sensitivity of these ears is extremely strong and need to strengthen the protection and the development intensity is low-intensity developed; The low sensitive and insensitive regions are mainly distributed in most areas such as Li county, Xihe county, Hui county and Cheng county which can be developed advisably.